DURHAM, N.C. -- Duke's defense has developed into a strength for the Blue Devils.

After years of struggles and bad statistics, the Blue Devils rank near the middle of the pack in the Atlantic Coast Conference in scoring defense and near the top of the league in holding off opponents that have pushed inside the red zone. Even more impressively, Duke (6-2, 2-2 ACC) hasn't allowed a fourth-quarter touchdown for four straight games heading into Saturday's home game against instate rival North Carolina State.

"You've got to stop people," cornerback Ross Cockrell said Tuesday. "When it's time to get a stop, to force a turnover or to hold them on fourth down, a lot of those times are in the second half. And that's when you've got to step up as a defense."

Coach David Cutcliffe is associated with high-scoring offenses and prolific passing attacks, dating to his days as a coordinator or head coach for Peyton and Eli Manning at Tennessee and Ole Miss. The defense had been slower to develop during his six years here, but it has held up its end of the bargain during a 3-0 month of October.

Duke shut out Navy and Virginia after halftime, then had four interceptions against Logan Thomas to beat Virginia Tech on Oct. 26 — a win that made the Blue Devils bowl eligible in consecutive season for the first time in program history.

Duke is seventh in the 14-team ACC by allowing 22.5 points per game. That's the lowest total for the program since the Blue Devils allowed the same average during the regular season in 1994, which was the last time the Blue Devils were bowl eligible before last year's six-win season.

Duke's pass defense is ranked fifth in the ACC, allowing an average of 216 yards per game.

By comparison, Duke had never been better than ninth in scoring defense or seventh in pass defense since the league expanded to 11 teams in 2004.

"We've done a nice job of adjusting and having things available," Cutcliffe said. "This goes all the way back to spring practices and rebuilding, if you will, this defensive system. (Coordinator) Jim Knowles has done a tremendous job in that regard. I think it's made it easier for us to adjust, to apply a few new things, to find things and bring them that we need in the second half. That's real. I think our conditioning level is real.

"The tempo and the pace that our offense goes and the tempo that we practice, defensively now, I think we've improved our process."

The Blue Devils also rank tied for second in the ACC in red zone defense for the best showing of Cutcliffe's tenure, according to STATS LLC.

Overall, Duke has allowed one touchdown in its last six quarters, with both of those games coming on the road. And that has the Blue Devils feeling optimistic that they can accomplish a lot more in November after losing five straight — including to Cincinnati in the Belk Bowl — to end last year.

"Our motto is to finish," Cockrell said. "That's something we've been talking about since the spring. ... Whether it's a drill or a game or a snap, that's what we want to do. I think you've seen that over the last four games."